Ray and others,

The competition over the islands, reefs and the like in the South China Sea IIRC is well documented in journals, although you need a good map to follow the claims.

The situation between PR China and others is not straight forward IMHO, partly as economic growth has distracted states from such competition and potential for conflict.

Nor is the situation between the PRC and the USA clear-cut. How many know non-military PRC agencies are aboard US Coast Guard vessels in the North Pacific? For 'fishery protection' IIRC.

Have a peek at 'Survival', the journal of the International Institute for Strategic Studies (IISS); in The February-March 2011 edition, in an article 'Policing the Waves:Maritime Paramilitaries in the Asia-Pacific' by Christian Le Miere (who is the IISS's resident export on matters naval), pgs. 133-145. Fascinating, especially the use of non-naval agencies by most nations.